Electronically controlled knitting machine



June 17, 1947. w LARKlN. 2,422,568

ELECTRONICALLY CONTROLLED KNITTING MACHINE June 17 1947 w. LARKIN2,422,568

LECTRONICALLY CONTROLLED KNITTING MACHINE Filed \0ct. 5, 1945 4Sheets-Sheelt 2 W. LARKIN `une 17, 1947.

ELECTRONICALLY CONTROLLED KNIT'IING MACHINE "Filed oct. 3,' 1945 y 4sheets-sheet 5 F fe.

June 17, 1947. W LARKIN l 2,422,568

ELECTRONICALLY CONTROLLED KNITTING MACHINE Filed Oct. 5, l1945 4Sheets-Sheet 4 Patented .une 17, 1947 ELECTRONICALLY CONTROLLED KNITTINGMACHINE Walter Larkin,

Norristown, Pa.,

assignor, by

mesne assignments, to Fidelity Machine Company, Inc., Philadelphia, Pa.,a corporation of Pennsylvania Application October 3, 1945, Serial No.620,114

12 Claims.

This invention relates to variable speed drives for knitting machines,and particularly to drives for circular knitting machines adapted forknitting seamless hosiery in tubular strip form, wherein each stockingunit includes a welt section, a leg section, a heel pocket, a footsection, a toe pocket and in most cases a separation or ravel sectionbetween units.

During the knitting of these different parts of each stocking unit it isfrequently necessary to change yarns or to add reinforcing yarns. Duringsuch changes of yarns, or the feeding or reinforcing yarns, and duringthe reciprocating action of the needle cylinder or the cam ringassociated therewith, and the corresponding reciprocating action of thesinker ring while knitting the heel and toe pockets, it has been foundto be desirable to Vary the knitting speed in relation to the normalknitting speed employed in the circular knitting of the leg and footportions of the stocking unit.

Also in knitting stocking strips from different base yarns, such asnatural thread silk, artificial silk, mercerized cotton, rayon, nylon orother synthetic lament yarns, it has been found advisable to establish apredetermined base speed for each of these types or qualities of yarnand to vary the speeds for knitting the different parts of each stockingunit from the established base speed in order to produce the highestquality fabric at the greatest possible speed.

These various speeds during the knitting of the different parts of astocking unit have been deemed necessary to prevent damage to theneedles, sinkers and other related parts of the machine and to thefabric `in order to prevent stoppages resulting from broken or bentneedles, etc., and in order to give a uniform stitch and a consequentuniform fabric free of needle or sinker marks.

The change speed mechanism of a circular knitting machine normallyaffords a high speed for continuous circular knitting and a slow speedfor reciprocating knitting, but no variation in speed for yarn changing,yarn reinforcing, or for knitting dierent kinds and/or weights of yarn.

The principal object of the present invention is to provide a verysensitive and readily variable speed mechanism to an. ordinary circularhosiery knitting machine, whereby the knitting speed of the machine maybe quickly and automatically changed and varied to any desired extentwith respect to the base speed established for knitting of theparticular kind or weight of yarn of which the major portion of thestocking strip is to be formed.

For the purposes of the present invention the type of change speedmechanism best suited for putting into effect the objects of the presentinventon is what is popularly termed the electronic motor control suchas disclosed in the following patents of the General Electric Company,through which such units are commercially available, i. e. U. S. PatentsNo. 1,654,949, No. 1,654,989, No. 1,655,036, No. 1,655,040, No.1,719,866, No. 1,847,- 934, No. 1,851,692, No. 1,904,485.

1n the present case no claim is made to this so-called electroniccontrol unit per se but only as to its application to a circularknitting machine broadly and more specically to a circular knittingmachine equipped with an ordinary pattern drum by which the shiftingfrom the continuous circular knitting to reciprocating knitting and viceversa are controlled and by which a plurality of yarn lingers areselectively moved into and out yarn feeding relation to the needles andsinkers of the machine for effecting yarn changes and reinforcementsetc.

These electronic control units are in themselves controlled, in thecommercial adaptations thereof, by a rotary type potentiometer, and inthe present instance the potentiometer is controlled vby the patterndrum of the knitting machine, whereby, as the pattern drum isintermittently rotated step by step a speed-control cam thereof willcontrol the position of the rotor element of the potentiometer withrespect to the stator element thereof to vary the speed of the knittingmachine in accordance with` the current operation of the machine asdirected by the pattern drum.

In the accompanying drawings:

Fig. l is a more or less diagrammatic side elevation, partly in section,of suicient of a conventional type of circular hosiery knitting machineto illustrate the present invention, and as would be Viewed along theline I--l, Fig. 2;

Fig. 2 is a vertical sectional elevation as taken on the line 2-2, Fig.1;

Fig. 3 is a diagrammatic planar development of the peripheral surface ofthe pattern drum shown in Figs. 1 and 2;

Figs. 4 and 5 illustrate a detail of the invention and show the meansfor establishing a base speed for the. knitting machine for onepredetermined kind of knitting yarn;

Fig. 6 is a diagrammatic View showing the motor circuit control unit asbeing operated directly from the pattern chain of the machine, and

Fig. 7 is an elementary circuit diagram for controlling the speed of the'driving motor of the knitting machine.

As shown in the drawings the cam ring 2 of the knitting machine, in thepresent instance, is held stationary and is rigidly secured to the topframe l of the knitting machine. The knitting or needle cylinder 3 is ofthe rotary type and is adapted to rotate about a vertical axis withinthe cam ring 2. The sinker ring mechanism is illustrated generally atil.

The needle cylinder 3 is provided with an integral bevel gear whichmeshes with and is rotated by a bevel gear 5, which latter is iixedlymounted for rotation on a horizontal shaft 'I. The shaft I is rotatablymounted in suitable bearings in opposite side frame members 8 and 9 ofthe machine.

Loosely mounted for rotation about the aXis of the shaft at oppositeends respectively of the hub ID of the bevel gear 6, are spur gears IIand I2 respectively. The spur gear I2 meshes with a spur gear I3 whichis rotatably mounted on a fixed stud shaft I4 carried by the side framemember 8. rlhe gear I3 meshes with a pinion I5 which is fixed to a jackshaft I6 having one end rotatably supported inthe frame member 8 and itsopposite end rotatably supported in a bracket I'I carried by the baseframe I 8 of the machine. f

Secured to the jack' shaft I 5 is a second spur gear IB which mesheswith a spur gear 20. The spur gear 2G is secured to a take-off shaft ZIwhich is rotatably mounted in the bracket II and a corresponding bracketIIa on the base frame I8. p

Secured to the take-off shaft 2l is a bevel gear 22 which meshes with abevel pinion 23, which latter is secured to the rotor shaft 24 of anelectric driving motor 25, said motor being rigidly fixed in and to thebase frame I8 of the knitting machine.

The spur gear I3, referred to above, is provided with a crank pin 2S onwhich is rotatably mounted one end boss or hub 21 of a pitman 28, theopposite end hub 29 of which is rotatable on a pin 3 secured in one arm3l vof a gear segment lever 32. The lever 32 is secured to one end of ashaft 33 which is Ymounted for oscillation in the framework of themachine. The lever 32 includes a gear segment 34 which is constantly inmesh with the'spur gear II at one end of the hub I I! of `the bevel gearwhich .drives the cylinder 3 through the bevel gear 5. Y

The hubl Ill of fthe gear 6 is splined axially at 35 for reception andoperation of a sliding clutch key 35. The key 35 is carried by a sleeve31 which is slidably vmounted on the outside of the hub I and isprovided with an annular circumferential groove 38 for reception of aclutch yoke 39.

The clutch yoke `39 is pivotally carried in the outer end of a clutchshifting lever 40 which latter is pivotally'mounted on a pinplll in aboss 42 on the under side of the top frame I of the machine. l

The clutch key 35 is shiftable longitudinally in the spline 35 of thegear hub I ll, into end grooves 23 and 44 in the gears I'I and I2respectively, so that the h-ub It may be rigidly coupled to the gear IIfor oscillating the needle cylinder 3 or to thegear I2 for rotating thecylinder 3.

The shifting of the clutch key 35 is effected by cam plates 55, 45, 'liland 48 secured to the peripheral surface 49 of the pattern drum 5i).

The pattern drum 5U is secured to a shaft 5I which is rotatably mountedin the framework of the knitting machine. Secured to the shaft 5I is a,ratchet wheel '52 which is engageable by a paWl "53 for advancing thepattern drum 5i) step The pawl 53 is pivotally mounted on a lever 54which is secured to the shaft 33. This'shaft 33 is continuouslyoscillated through the arm'SI and 4 pitman 28 from the crank pin 26 onthe continuously rotating gear I3.

The pawl 53 is held out of mesh with the ratchet wheel 52, atpredetermined intervals by a kick-out arm or latch 55 Which is pivotallymounted on the frame and operates against a pin 55 which projectslaterally from the pawl 53. The latch l55 in turn is controlled by highlinks of a pattern chain (not shown) which rides on a chain wheel '5l'engaging one arm 58 of the latch 55.

The chain Wheel 5l is freely rotatably mounted on the pattern drum shaft5I and is advanced step by step by a ratchet wheel 59 which is securedto the chain wheel 5l for rotation therewith. The ratchet wheel 59 isadvanced step by step by a paw] Et pivotally mounted on the pawl lever5d secured to' the constantly oscillating shaft 33.

On the peripheral face 129 of the pattern drum 55 is a plurality ofsegmental circumferentially arranged and laterally spaced cam pieceseries 6I, 5I, which control the operation of a plurality of yarn changelingers 52, 52 etc. through lift levers 53, 63 respectively. These liftlevers 63, 63 are pivotally mounted on a cross shaft 54, which isnon-rotatably mounted in the frameworkv of the knitting machine.

Pivotally mounted on the shaft 64 is a lever 65 on which is rotatablymounted a cam follower roller 65.' rhis cam follower 55 is adapted toride high, low and intermediate lifts 67a, B'Ib, 61o, of a ring cam @lsecured to one end of the pattern drum 52. There may be as many of theselifts as there are speed variations required of the driving motor 25during the knitting of a complete repeat in the string of stocking unitsknitted by the needles (not shown) operating in the needle grooves ofthe cylinder 3 by the cams (not shown) in the cam ring 2.

The speed Variations of the driving motor 25 are controlled by theelectronic unit referred to above as being disclosed in one or more ofthe prior U, S. patents listed above.

The electronic control unit in turn is controlled by a potentiometer l,see F'igs. 4 and 5, which includes an outer casing 'II which for thepurposes of this disclosure will be termed the stator, and an internalelement secured to a shaft 'I2 which will be hereinafter referred to asthe rotor.

'The specific construction of the potentiometer 'MI need not be shown ordescribed in l'detail as it is of va conventional type well known as toconstruction and mode of operation by anyone having the most elementaryknowledge of electricity.

For the purpose of this invention, the stator 1I is axially aligned andconcentric with the rotor shaft 'I2 of the potentiometer 'le and the'shaft I2 is rotatably mounted in a bearing 'i3 mounted in a bore 'Iiiformed in the side frame 8 of the knitting machine.

In order to retain the stator in a fixed predetermined position forsetting the potentiometer for :maintaining the speed of the motor 25,through the electronic unit disclosed in theaforesaid prior U. S.patents, at a predetermined number of revolutions per minute, a's a basespeed for anygiven knitting yarn, the stator is secured to an arm i5having a spring pressed detent i6 at its outer end for entering one of aplurality of openings il, 'Il formed in the side frame 3, so that thestator 'II may be bodily turned about the axis of the rotor shaft 'I2 toany one of the angular positions determined by the location of thekeeper holes TI.

'The rotor, as is common in potentiometers, is adapted to be turnedwithin the stator to increase or decrease the Voltage of the line of theelectric circuit in which the potentiometer is installed, depending uponthe direction in which the rotor is turned, and in order to effect suchturning of the rotor within the stator 1i the rotor shaft 12 is providedwith a spur pinion 118 Which meshes with a gear segment 19, which latteris rigidly secured to the lever 65. The lever 65 as previously notedcarries the cam follower et and this cam follower is maintained inconstant contact with the speed control cam 61 by a spring 80.

From the forego-ing description, it will be clear that once a base speedfor the motor 25 is established for a given knitting yarn, by insertingthe spring pressed detent 16 in one of the keeper holes 11, greater orlesser speeds of the motor 25 may be attained by turning the rotor shaft12 of the potentiometer with respect to the stator, i. e. turning theshaft 12 in one direction will effect an increasein the speed of themotor 25 and turning the shaft 12 in the opposite direction will effecta decrease in the speed of the motor 25.

It will also be clear that the speed changes of the motor 25 arecoordinated with the various mechanical changes etc. in the operation ofthe knitting machine as determined by the step by step movements of thepattern drum 5B, by reason of the fact that the high, low andintermediate lobes of the speed change cam 61 bear definite xed relationto the cam segments #l5 to e8 and Gl, 5I on the pattern drum 50 by whichsuch mechanical changes in the operation of the knitting machine arecontrolled. Y

It will also be clear that by varying the relative heights of the lobeson the speed change cam 61 and distributing them discriminately aroundthe circumference of the pattern drum 5) an infinite number ofrelatively dfferent speeds, Within a given bracket, may be caused to beeffected by the motor 25; and that by changing the position of thestator about the axis of the rotor shaft these speed brackets may bechanged in accordance with the different knitting yarns employed, or forother reasons if desired.

As shown in Fig. 6, the potentiometer 'it may be controlled directlyfrom the pattern chain of Y is actuated by a pinion 1e on the rotorshaft 12 thereof, and this pinion 18 meshes with a gear segment 1Sloosely mounted on the shaft te. In the present instance, Fig. 6, thegear segment 19a is secured to one end of a cross shaft 64a and the camfollower arm 65 of Fig. 1 is replaced by an arm 65a. secured to thedistant end of the shaft 64a. This arm 65a has its outer end shaped toride the high, low and intermediate links 81a, 81h, 81C of the patternchain 81 to rock the shaft 6M to varying degrees for correspondinglyoscillating the roto-r of the potentiometer.

Fig. '1 sho-Ws the electronic circuit for controlling the speed of themotor 25, through the adjustment of the potentiometer 10. The motorarmature is represented at 9G, while the motor field is represented at9i. The field current is sup-plied from a transformer 92' by means of afull wave rectiiier 93, while the armature is supplied with current fromthe transformer 52 through a pair of controlled rectiers 94 and 95. Asindicated, the tubes 93, 94, and 95 are gaslled tubes. The potentiometer1 serves in con- `junction with a tube 96 and a potentiometer 91 tocontrol the operation of tub-es 9:1 and 95 through the grid circuitsthereof designated generally by reference character 98. The details ofoperation are unimportant here, since the electronic control circuit isold per se and the present invention is concerned only with theoperationof the potentiometer 10 by the pattern mechanism of the knittingmachine.

I claim:

1. A circular knitting machine comprising an individual electric drivingmotor, pattern mechanism for governing predetermined operations of saidmachine, an electronic speed control circuit for and including saidmotor, a variable control unit for said circuit, and means coordinatedwith said pattern mechanism for operating said variable control unit forvarying the speed of said motor in accordance with changes in theoperations of said machine as prescribed by said pattern mechanism.

2. A circular knitting machine comprising a pattern drum for governingpredetermined operatio-ns of said machine, an individual electriedriving motor for said machine, an elec tronic speed control circuit forand including said motor, a variable control unit for and forming partof said circuit, said variable unit comprising a normally fixed elementand a relatively rotatable element, means for turning said rotatableelement relative to said fixed element including a cam follower, and acam comprising a plurality of lobes of different heights carried by saidpattern drum andy engageable with said cam follower for actuating saidunit to eiect variations in the speed of said motor in accordance withvariations in the operations of said machine as prescribed by saidpattern drum.

3. A circular knitting machine comprising a pattern drum for governingpredetermined oper.- ations of said machine, an individual electricdriving motor for said machine, an electronic speed control circuit forand including said motor, a variable control unit for and forming partof said circuit, said variable unit comprising a normally Xed elementand a relatively rotatable element, means for turning said rotatableelement relative to said fixed element including a cam follower, a camcomprising a plurality of lobes of different heights carried by saidpattern drum and engageable with said cam vfollower for actuating saidunit to effect variations in the speed of said motor within apredetermined range in accordance with variations in the operations ofsaid machine as prescribed by said pattern drum, and manually operablemeans for varying the position of said normally fixed element about theaxis of rotation of said rotatableelement for varying said range as a`whole from one bracket of speed variations of said motor to anothersuch bracket.

4. A circular knitting machine comprising an individual electric drivingmotor adapted to rotate in one predetermined direction, a pattern drumfor governing predetermined operations of said machine, an electronicspeed control circuit for controlling the lspeed of said motor in saiddirection solely, and means carried by said pattern drum for controllingsaid circuit to change 7 the speed of said motor in said directionsolely in accordance with changes in the operations vof said machine asprescribed by said pattern drum.

5. A circular knitting machine comprising an individual electric drivingmotor, a pattern drum for governing predetermined operations of saidmachine, a variable unit for controlling the speed of said motor, saidunit comprising a normally Xe'd =element and a relatively rotatableelement, a lever for rotating said rotatable element, and a cam carriedby said pattern drum for rocking said lever and thereby actuating saidunit to change the speed lof said mot-or in accordance with changes inthe operations of said machine as prescribed by said pattern drum.

6. A circular knitting machine comprising an individual electric drivingmotor, a pattern drum for governing predetermined operations of 'saidmachine, a variable unit for controlling the speed of said motor, saidunit comprising a-normally xed element and a relatively rotatableelement, a lever for rotating said rotatable element, a cam carried bysaid pattern drum for rocking said lever and thereby actuating said unitto change the speed of said motor in accordance Withl changes in theoperations of said machine as prescribed by said pattern drum, andmanually operable means for rotating said normally fixed element to varythe range of speed lchanges of said motor.

'7. A circular knitting machine comprising a pattern drum for governingpredetermined operations of said machine, an individual electric motorfor driving said machine, a potentiometer for varying the speed oi saidmotor, and means on said pattern drum for actuating -said potentiometerto change `the speed of said motor in accordance with operationalchanges of the machine as prescribed by said pattern drum.

8. A circular knitting machine comprising a pattern drum for governingpredetermined opere ations of said machine, an individual electric motorfor driving said machine, a potentiometer for varying the speed of saidmotor and comprising a rotor shaft, a pinion on said shaft, a gearsegment meshing with said pinion, a lever cor1 centric with andintegrally connected to said gear segment for concurrent pivotalmovement about a xed axis, a cam follower on said lever, and `a ring camsecured to said pattern drum `and including a plurality of lobes ofdifferent heights spaced circumferentially around said drum forsuccessively contacting said cam follower to'actuate said potentiometerfor varying the speed kof said motor in 'accordance with operationalchanges of said machine as prescribed by said lpattern drum.

'9. A circular knitting machine comprising a pattern drum for governingpredetermined operations of said machine, an individual electric motorfor driving said machine, a potentiometer for varying the speed of saidmotor and comprising a rotor shaft, a normally iixed stator encirclingsaid rotor shaft, a pinion on said shaft, a gear segment meshingWith'said pinion, a lever concentric with and integrally-connected tosaid gear segment for concurrent pivotal vmovement about a fixed axis, acam follower on said lever, a ring cam secured to said pattern drum andincluding a plurality of lobes 0f different heights spacedcircumierentially around said drum for successively contacting said camfollower to actuate said potentiometer for varying the speed of saidmotor in accordance with operational changes of said machine asprescribed by said pattern drum, an operating arm on said stator,

and a manually operabl'edetent on the 'outer end of said arm adapted tobe selectively entered into a plurality of fixed relatively spacedkeeper holes formed in said machine for varying the speed ranges of saidmotor within predetermined brackets respectively .in accordance with thekeeper hole entered by said detent.

10. iA circular knitting machine comprising a pattern drum for governingpredetermined operations of said machine, an individual electric motorfor driving said machine, a potentiometer for varying the speed of saidmotor and comprising a rotor Shaft, a normally xed stator encirclingsaid rotorxshaft, a pinion on said shaft, a gear segment meshing Withsaid pinionfa lever concentric with and integrally connected to saidgear segment for concurrent pivotal movement about a xed axis, a camfollower on said lever, a ring cam secured to said pattern drum andincluding a plurality of llobes of different heights spaced'circumferentially around said drum for successively contacting said camfollower to actua-te said Apotentiometer for varying the speed of saidmotor in accordance 'with operation-al Achanges of said machine asprescribed by said pattern drum, an operating larm on said stator, amanually operable detent on the outer end of said arm adapted to beselectively entered into a plurality of xedrelatively spaced keeperholes formed in said machin-e for varying the speed ranges of said motorWithin predetermined brackets respectively in accordance with the keeperhole entered by said detent, and an electronic motor control lcircuitincludingsaid driving motor and said potentiometer forgoverning thespeed of said motor in accordance with the circumferential relationshipof said rotor shaft and said stator as prescribed .by said detent andsaid ring cam.

11. A circular knitting machine comprising an individual electricdriving Ymotor therefor adapted to -rotate in one predetermineddirection, pattern ,mechanism for governing predetermined operations ofsaid machine, an electronic speed -control circuit for varying thespeedfof said motor in said direction solely, and means carried by saidpattern mechanism for controlling said circuit.

12. A circular knitting machine comprising an individual electricVdriving motor therefor adapted 'to 'rotate in one `predetermineddirection, pattern mechanism including 'a link chain `lor 'governingpredetermined `-operations of said machine, an electronic speed controlcircuit `for controlling the speed of said Vmotor n'said directionsolely, and a series of links of different heights included in saidpattern chain for controlling said circuit to vary the speed of saidmotor in said direction solely. a

WALTER LARK'IN.

REFERENGES CITED The following vreferences are of record in the le ofthis patent:

U-NTTED STATES PATENTS Number i Name Date 1,123,779 Moller Jan. 5, 19152,068,609 Richter Y Jan. 19, 1937 FOREIGN 'PATENTS Number Country Date1397,793 Great Britain Aug. 31, 1933 172,357 Great Britain NoV. `30,1921 439,713 Germany Jan, 1-8, l1927

